How To Prune Tomatoes
The need to prune tomato plants depends on the type of tomato plant it is. Plants that grow upwards with a central stem, called indeterminate tomatoes, do need pruning, whilst bush or tumbling varieties do not need pruning.
Watch the video, or scroll down to continue reading. You may like to see this page on how to grow tomatoes.
Apart from checking the seed packet, if your tomato plants looks like the one shown, pruning the plant is a good idea.
This will concentrate the plant’s energy into fruit production, rather than making new stems and leaves.
Determinate varieties, like many cherry and tumbling types, do not need pruning and naturally form a round bush shape. If you were to prune you would significantly reduce the tomato harvest.
There are two main types of stems to look out for when starting to prune tomatoes. The first are the suckers that grow at the elbow of the main stem and a side branch. These are easy to pinch out with your fingers or scissors.
The second are suckers, or runners, that grow up from the base of the plant. I find these easy to miss due to concentrating more at the top of the plant. These runners can grow very quickly, and are easy to identify by their vertical growth habit. They can be easily cut or snapped off.
Once you have started to prune your plants, it is easy to spot the difference between the suckers and the actual fruit clusters, or trusses. These trusses do not typically form at the stem and branch elbow, but spring out from a straight section of stem. If there is any doubt, simply leave them on the plant and see if they form flowers or leaves.
Unfortunately, the British summer only lasts so long, whilst a tomato plant will continue to grow upwards and onwards creating new stems and leaves. For this reason, around August and providing you have six or seven flower trusses, it may be worth cutting out the growing tips at the top of the plants. This will divert the energy into the remaining fruit.
Whether growing indoors or outdoors, you will need to support indeterminate tomatoes. What look like thick stems soon topple over with the weight of the growing fruit.
The resulting tomato plants should look much neater after pruning, and if growing in pots, pruning this way will also allow you to group your plants closer together, making better use of space.
Although it is possible to grow tomatoes outdoors in a sunny situation, it is easiest to grow them inside a greenhouse, polytunnel, or plastic greenhouse.